The main purpose of this research is to understand how opiates affect certain biochemicals which are synthesized by nerve cells. It is possible that alterations in the synthesis of these biochemicals relate to the effects of opiates in their amelioration of pain and in their causation of physical dependence. The substances which are being studied include cyclic nucleotides (cyclic AMP and cyclic GMP), prostaglandins and endogenous peptides with opioid action. These compounds may be involved directly or indirectly with neurotransmission in the central nervous system. Cultured cells of nervous tissue origin (clones of mouse neuroblastoma) are being used for these studies. As a model system these cultured cells offer a number of advantages for such studies, including being able to visualize the cells as well as assay them biochemically and electrophysiologically. It is hoped that the results of these studies will increase our understanding about the mechanism of action of opiates with respect to pain pathways and to opiate addiction.